I've got five, all fully functional -- but could easily pare that down to three.
Hardtail Schwinn MTB from college: haven't ridden it much in years.
Bad Boy Disc: bought it while getting the MTB repaired, and enjoyed it a lot until I got...
CAAD8: fun, fun bike. It's a keeper. Gets the most mileage, but I don't like collecting muck while riding it in the rain. So I got...
Schwinn DBX: cyclocross-style bike, with discs & full fenders. Not as fast as the CAAD8, but it rides fine, and is much better suited to rain & puddles. I'll keep this one around, too.
C'dale Rush: my first nice MTB. I even put the Bad Boy's 700x28 wheels on it today. Really an excellent bike. It has almost made both my MTB and Bad Boy redundant.
I should sell the old MTB and Bad Boy, and keep the other three. I'll be happy for quite a while.